Question

for his birthday, ben got a bubble machine. he was so excited that he played with it all day! in the morning, he used 1 liter of bubble mix. after lunch, he used 3 more liters. how much bubble mix did ben use in all? liters

Explanation:

Step1: Identify the amounts used

Morning use: $1$ liter. After - lunch use: $3$ liters.

Step2: Add the amounts

To find the total, we add the two amounts: $1 + 3=4$.

Answer:

4